Peak use (demand) is the maximum energy need for an hour – set by the member – for the utility to have available at all times to meet everyone’s maximum needs during peak hours.
Energy use, also referred to as consumption, is the total amount of energy used by the member – usually over a longer period, such as a whole month.
If a 100-watt lightbulb is on for 10 hours, it consumes 1,000 watt-hours. The entire time it's on, it demands 100 watts or .01kW from the utility. That means Cobb EMC must have that .01kW ready whenever the member turns on the lamp.
Similarly, ten 100-watt lightbulbs burning for 1 hour consume 1,000 watt-hours or 1kWh.
Note that in both examples, the energy use is 1kWh, however, notice how the second situation impacts the utility from a demand perspective. Cobb EMC must now be prepared to provide ten times as much capacity in response to the demand of the 10 lightbulbs operating all at once.